You cannot apply raid marks to enemy player targets in Arenas and Rated Battlegrounds (at least you couldn't last expansion).

You can keybind the marks in the keybinding menu.

Yeah. That has annoyed me a bit at times.
Why is it so? People are on teamspeak and can use "assist" so basically you can just tell them to assist you on your target, and rip them to peices, instead of having them marked?
It only seems to give people not using TS a disadvantage.

For my team, when i join the arena :P like "green mark on me, blue on one of my team mate, and skull on my orther team mate"

I don't think you can macro marks. At least i've seen posts here back in cata saying you couldn't.
But it's not like it's slow to mark things if you just bind it to some keys? you have plenty of time during preperation for it?